基于Newmark模型的尼泊尔M_s8.1级地震滑坡危险性快速评估

在研究分析地震灾区地形地貌、地层岩性、地质构造、气象水文和典型地区滑坡的基础上,采用Newmark斜坡累积位移模型对2015年4月25日尼泊尔M_s8.1级地震诱发的滑坡危险性的空间分布状况进行了快速评估,通过典型地区的滑坡遥感解译结果验证表明评估结果具有较好的可信度,初步反映了尼泊尔地震诱发滑坡危险性分布的基本特征。然后考虑降雨作用对震后滑坡危险性的影响,对地震叠加降雨诱发滑坡危险性分布进行了快速预测。研究结果对地震应急救灾中的地质灾害防灾减灾具有重要的参考意义。

LANDSLIDE HAZARD RAPID ASSESSMENT IN THE Ms 8.1 NEPAL EARTHQUAKE-IMPACTED AREA, BASED ON NEWMARK MODEL

April 25, 2015, an M_s8.1 earthquake occurred in Nepal with epicenter of 28.2°N, 84.7° E and focal depth of 20 km. The earthquake and induced landslides caused serious casualties and economic losses in Nepal and southwest Tibet of China. After the earthquake, the earthquake-induced landslide hazard distribution offered information to timely relief activities. Based on the detailed analysis of geomorphology, lithology, tectonics, hydrology and typical landslides, the sophisticated Newmark model and Geographic Information System were adopted to complete the rapid assessment of landslide hazard distribution in the Nepal earthquake-impacted area. The assessment results had good confidence by the verification in terms of landslide cases coming from remote sensing interpretation in partial regions and initially reflected the basic characteristics of Nepal earthquake-induced landslide hazard distribution. Then, considering the post-earthquake rainfall effect that can significantly initiate landslides, the landslide hazard rapid assessment under the combined effect of seismic motion and heavy rainfall was completed. The landslide hazard rapid assessment results can provide important references to geo-hazard prevention and mitigation during post-earthquake emergent relief activities.